JPS6052365A - Thermal recording head - Google Patents

Abstract

PURPOSE:To increase the capacity of power source and the speed of operations as well as enhance the operability of assembling by a method in which heating section and IC section are provided on a common supporter, and common electrode wiring for the IC section is provided on the back side and/or surface side of a film carrier tape. CONSTITUTION:A heating section 2 and IC chips 4 are provided together on a base plate 1 as a common supporter. A printed substrate 5 on which the IC chips 4 are mounted is set separately with a spacing in the face of a resistor plate 3 on the heating section 2 side. Each wiring 12 on the printed substrate 5 and the signal electrode wiring 10 on the heating section 2 side are connected electrically and mechanically by the lead 15 of a film carrier tape 7. In this case, one tape 7 is used for plural IC chips 4. A common electrode wiring 17 for each IC chip 4 is formed on the substrate 5 at the same time as the wiring 18 is formed on the back of the occupying region of the film carrier tape 7. Since insulating separation from the wiring 15 is permitted by the tape 7, a power source line having good reliability can be formed without the needs to increase the number of processes.

Description

[Detailed description of the invention] 1. Industrial application field This invention relates to a thermal recording head manufactured by the present invention.

2. Prior art A thermal recording head (hereinafter simply referred to as a head) performs recording while in contact with a recording medium such as recording paper or thermal paper, either directly or via an ink expansion film. The heating section is selectively heated in the form of a dot by an electrical signal, and an image, etc., can be recorded on the recording medium using this heating section.

In conventional heads, a heating layer is generally provided on the substrate, and a number of opposing electrodes are formed on this layer to form the heating section, and an integrated circuit is placed outside the substrate for the (!) electrodes. (
Hereinafter, it will be referred to as IC. ) is used to give a signal corresponding to the desired image pattern.

However, since one IC section is attached externally,
The IC section requires its own arrangement space, and there are problems in terms of electrical connection (usually a lead wire connection) with the heat generating section, reliability, workability, etc. In addition, the power supply capacity of the IC part that operates the heat generating part should be larger than usual (for example, 50
V, 20 mA) is necessary for sufficient heat generation control operation.

On the other hand, Japanese Patent Application Laid-Open No. 57-53370 discloses a head in which a heat generating part is provided on a base body and this heat generating part is operated by an IC part mounted on a so-called film carrier tape. There is. However, this known head has the following serious drawbacks.

(1) Since the IC part is not provided on a common substrate with the heat generating part, but is provided on the film carrier tape, it is necessary to apply each wiring related to the IC part in a fine pattern on this tape itself. Yield tends to decrease.

(2) Since the common power supply wiring □ of the IC part is provided on the film carrier tape, the space for the power supply wiring is considerably simulated, and therefore the effective area for wiring such as low power wiring and control wiring of the IC part is reduced. For this reason, the degree of integration decreases, and in particular, the number of signal electrode wires directed toward the heat generating portion cannot be provided at 8 wires/mL, resulting in poor image resolution during recording.

(3), L, on the film carrier tape, the IC
Since there is a region where the common power supply wiring of the section and the lead connected to the signal electrode run in parallel, stray capacitance occurs between the two in this region, slowing down the signal transmission speed. For example, if the ability to send a signal at 10MHz is required, 2M
Only signal frequencies of Hz are available. This phenomenon cannot be avoided even if the number of wirings is increased and the degree of integration is increased. To provide a head whose power supply capacity can be effectively increased without reducing the degree of integration, and whose operating speed can be increased even when the degree of integration is increased.

4. Structure of the invention and its effects, that is, the present invention provides a heat generating section and an integrated circuit section (IC section) that operates the heat generating section, which are provided on a common support, and a signal electrode to the heat generating section. The wiring and the IC part are electrically connected to each other via a film carrier tape, and the common electrode wiring of the IC part is provided on the back side and/or the front side of the film carrier tape. This relates to a thermal recording head.

According to the present invention, since the IC section and the heat generating section are provided on a common support, the structure can be significantly simplified or made more compact compared to conventional heads in which the IC section is externally attached. In addition, since the IC part can be set by fixing it on a common support and electrically connecting it to the wiring pattern formed on the support, the IC part can be set and the heat generating part can be electrically connected. It becomes possible to improve the reliability of the connection and also improve its workability.

Further, according to the present invention, the common electrode wiring (particularly the power supply wiring) of the IC part is provided on the back side and/or the front side of the film carrier tape between the signal electrode wiring to the heat generating part and the IC part. , a part of the area occupied by the film carrier tape can be effectively used as a power supply wiring area for the IC section, and this can also be used for other wiring (for example, the output line from the IC section to the above signal electrodes or the IC section This can be realized without affecting the area (control wiring). Therefore, the power supply wiring for the IC section can be provided without reducing the degree of integration of the head, and the power supply capacity can be increased by this power supply wiring, which is extremely convenient for reliable operation.

Furthermore, in the present invention, an IC is provided on the film carrier tape.
Since the common electrode wiring (particularly the power wiring) of the IC part is provided under and/or above the film carrier tape, the yield of the film carrier tape is improved, and at the same time, the common electrode wiring of the IC part is provided. The effective area for other wiring can be taken sufficiently large, and the degree of integration itself can be greatly improved (for example, the number of signal electrode wiring to the heat generating part can be increased from 12 to 16).
book/■) is possible. Furthermore, since the common electrode wiring can be provided in such a way that the stray capacitance between the common electrode wiring and other wirings is greatly reduced, the signal transmission speed is greatly improved, and in particular, it becomes possible to send signals at 10 MHz. Therefore, the head of the present invention has a high operating speed even if the resolution is high.

5. Examples Hereinafter, the present invention will be described in detail with reference to examples.

First, the basic structure of the head according to this embodiment will be explained with reference to FIG.

According to this head 20, on a common substrate (for example, an aluminum substrate) 1, a resistor plate (for example, a ceramic plate such as alumina plate) 3 provided with a heat generating part 2 and a large number (for example, 64
A printed circuit board (for example, a glass epoxy or ceramic board) 5 on which two IC chips 4 are fixed is fixed facing each other with a certain gap 6 therebetween. Electrical connection between the IC chip 4 and the heat generating section 2 is made by a film carrier tape 7 that is stretched between the printed circuit board 5 and the resistor plate 3 above the gap 6.

This connection method is explained in detail in FIGS. 2 to 4. The heat generating part 2 is made of aluminum, for example, which is formed on a heat generating body (for example, tantalum nitride) layer 8 deposited on the resistor plate 3. A common ground electrode 9 and a ground electrode 9 on the same heating element layer 8
It is formed by each facing portion 11 with a number 4a electrode 10 made of aluminum, for example, which is arranged in a longitudinal direction. On the other hand, each IC chip 4 has a fixed number of
The wiring 12 made of aluminum, for example, is mounted on separate printed circuit boards 5 that are joined to each other at separation lines indicated by 30, and is provided in a predetermined pattern on the printed circuit board 5.
etc., are wire-bonded using a wire 13 made of Au or At. Note that each of the above wiring patterns is shown in a simplified diagram.

The film carrier tape 7 is, for example, a polyimide substrate 1.
4, a number (for example, 64) of glues 15 made of copper foil, for example, are adhered to the number corresponding to the signal electrodes 10 and wirings 12. The connections between these leads 15, the signal electrodes 10, and the wiring 12 may be made by a so-called beam lead method, in which both ends of the leads 15 are slightly overhanged in advance, and the connections are made by thermocompression bonding. I can do it.

The IC chip 4Ii may actually have 56 pads, of which 32 pads are used for the output wiring 12 and 8 pads are used for the data transfer, control and ground wiring 16. As clearly shown in FIG. 3, the remaining 16 pads are wires 18 to a common power supply wire (sometimes referred to as a "return line" from the power supply) 17 between each IC chip. used for.

In this case, as shown in FIG. 5, the power supply wiring 17 is provided along the edge of the printed circuit board 5 on the back side of the substrate 14 of the film carrier tape 7.

It should be noted that the formation of each electrode or wiring 6, mounting of the IC chip, and wire bonding described above can be performed by known semiconductor device technology, so detailed explanation thereof will be omitted. Although not shown in the drawings, in FIG. S
A heat retaining layer such as an insulator or a film is laid down, and its heat retaining effect reduces the power supply and accurately controls the thermal cycle.

The head constructed as described above has excellent functions and effects not found in conventional heads, as shown below, and is an extremely useful and highly practical device.

First, what is important is that the IC chip 4 and the heat generating section 2 are provided on the base 1, which is a common support, and this makes the head configuration extremely simple and compact. In this case, the IC part in particular is mounted by mounting the IC chip 4 and wire bonding to the wiring, but the heat generated from the IC chip 4 during operation is dissipated through the underlying substrate 5 (and 1). Heat destruction of IC can be effectively prevented. In addition, since the printed circuit board 5 is arranged to face the resistor plate 3 on the side of the heat generating section 2, separated by the above-mentioned gap 6, most of the heat generated in the heat generating section 2 is transferred to the printed circuit board 5 side. In this respect as well, the IC section can be effectively protected.

Another advantage of arranging the printed circuit board 5 and the resistor plate 3 separately as described above is that by configuring them in this way, the width of the resistor plate 3 itself can be narrowed (i.e., it can be made narrow and elongated). ), it is easy to load the resistor plate 3 into the sputtering device when forming the heating element layer 8 by sputtering, for example, and the number of resistor plates processed at one time can be increased. This will improve mass productivity.

Moreover, the printed circuit board 5 on which the IC chip 4 is mounted is
As shown in FIGS. 1 and 2, it is also important that each IC chip is provided separately for a certain number of IC chips. this is,
There is a remarkable effect in relation to wire bonding of IC chips. As is generally known, the yield rate during fully automated wire bonding is said to be o,99s (99,sl) due to factors such as deviations in the bonding position.
The number of wires (n) is assumed to be (0,998) depending on K.

Therefore, unlike the above, if a large number of IC chips are mounted on only one printed circuit board, and the total number of wires is, for example, 3000, the yield will be excellent.

(0,998) may be 0.0025. On the other hand, if the printed circuit board 5 is divided into several parts as in this embodiment, the number of IC chips (and therefore the number of wires) on the printed circuit board can be reduced, so the number of IC chips on each printed circuit board 5 can be reduced to, for example, 500. Therefore, the wire bonding yield is (0,9
98) Medium 0.3675. Therefore, by dividing the printed circuit boards into a plurality (for example, six) of K as in this embodiment, the yield can be greatly improved.

The IC chip 4 is mounted on each printed circuit board 5, and after wire bonding, each printed circuit board 5 is fixed onto the base l by adhesive or the like. However, the surface is not flat as a whole. For this reason, if only one printed circuit board is fixed on the base 1, the adhesion between the two is poor, and poor adhesion is likely to occur. However, according to this embodiment, since the printed circuit board can be divided and individually fixed onto the base 1, the influence of the surface properties of the base 1 can be alleviated compared to the above, and the individual printed circuit boards 5 can be tightly attached to the base 1. The adhesive properties are good and the adhesive strength is improved. In addition, since the position of each printed circuit board 5 can be determined independently when it is fixed, for example, each wiring 12 can be determined for each lead 15 on the film carrier tape 7.
It is possible to position each printed circuit board 5 so that each printed circuit board 5 corresponds as accurately as possible, and to have a degree of freedom in its adjustment.Furthermore, according to this embodiment, the printed circuit boards 5 whose positions have been adjusted as described above can be 5 and the signal electrode wiring 10 on the side of the heat generating part 2 are electrically (and mechanically) connected by the beam lead method using the leads 15 of the film carrier Chigua, and in this case. One tape 7 is used for a plurality of IC chips 4 (for example, two in the drawing). 1 for 1 IC chip 4
Although it is possible to use a single tape 7 for multiple ICC tapes as described above, it is possible to reduce the number of film carrier tapes used for the entire head and reduce the cost of this component. It will be possible to achieve this goal. Since the film carrier tape 7 of this example has each IC chip 4 mounted on a separate printed circuit board 5, it is only necessary to provide the Cu leads 15 as wiring in a predetermined pattern, and the pattern can be simplified. Moreover, all the IC chips 4 are arranged on the printed circuit board 5 side, and the wiring 12
, the lead 15 and the wiring 10 are connected to the heat generating part 2, so it is possible to increase the mounting density of the IC chip, and the tape 7 can be easily formed with a number of leads corresponding to the number of wires using a known metallizing technique. and can be formed accurately.

Furthermore, a noteworthy feature of this embodiment is that the common power supply wiring 17 for each IC chip 4 is provided on the back side of the occupied area of the film carrier tape 7, as shown in FIGS. 3 and 5. It is. Therefore, the power supply wiring 17 that is provided to increase the power supply capacity (for example, to 50 Vs 20 mA) can be provided by effectively utilizing the film carrier tape area, without substantially affecting other wiring areas. Because there is no head, it is possible to maintain a high degree of head integration. For example, ■The number of output wiring from the C chip, that is, the number of signal electrodes to the heat generating part, can be significantly increased compared to the conventional one, from 12 to 1.
6 wires/wi, which greatly improves the resolution.In addition, since the area where the power supply wiring 17 and other wiring are lined up in parallel is significantly reduced, the floating capacitance between them is greatly reduced. The signal transmission speed can be greatly increased. For example, even if a signal transmission capability of 10 MHz is required, that capability can be almost completely satisfied. In addition, the power supply wiring 17 can be formed on the substrate 5 at the same time as the wiring 18 by vapor deposition → etching process, and can be insulated and separated from the wiring 15 on the film carrier tape 7 by the tape 7 itself, so reliability can be improved without increasing the number of man-hours. This means that a power line can be formed with good accuracy.

FIG. 7 shows the main parts of a head according to another embodiment of the invention.

In this example, the wiring 1Ij18 to the power wiring #j17 described above is
is commonly provided between each chip 4, and each pad of both chips is connected to this wiring 18 by wire bonding.

This type of connection method not only provides the same effect as the previously described example, but also facilitates the formation of wiring since both chips are connected to the common wiring 18, and also reduces the area occupied by the wiring. FIGS. 8 to 10 show still other embodiments of the present invention.

According to this example, the power supply wiring 17 of the ICC tag is provided on the surface side of the substrate 14 of the film carrier tape 7 as shown in FIG. 9, and is connected to the wiring 12 on the printed circuit board 5 by, for example, a beam lead method. . On the other hand, the first connection between the output wiring 12 and the lead 15 of the film carrier tape 7
As shown in FIG. 0, the lead 15 is guided through the through hole 19 to the back surface side, and the exposed end of the tape substrate 14 from the back surface is connected to the wiring IIj 112.

In this connection method, each wiring #15 and 17 is prepared in advance on the film carrier taper itself, and can be connected to the corresponding wiring 12 and 18, respectively, after the tape is attached (adhered). Therefore, the positional relationship of the wiring lines 15 and 17 can be determined accurately at the time of manufacturing the tape 7.

Next, a thermal recording method and apparatus using the heads according to the above-described embodiments will be explained.

According to the example of FIG. 11, in a thermal transfer type thermal recording device 39 in which the head 2o mentioned above is brought into contact with the recording paper 33 via an ink film 41, various devices for thermal recording are installed inside the case. The incorporated 0 recording paper 33 is stored in a folded state in a cassette 34, for example, and is sent to a thermal transfer section 36 via rollers, and after being transferred, it is discharged out of the apparatus as shown by arrow A.

The ink film 41 is sent from a supply roll 42 to a thermal transfer section 36 via a guide roller 43 and a drive roller 44, and then taken up from KKMh b-, r-45.
-46. Note that the ink film 41 is configured such that a heat-melting ink (not shown) is applied, for example, between the supply roll 42 and the guide p-2-43.

In the moving path of the ink film 41, a seven-dimensional sensor (for example, an infrared light sensor) 47 for detecting the ink film 41 coated with heat-melting ink is arranged in front of the drive roller 44.

A photosensor (for example, an infrared light sensor) 49 is arranged in front of the pressure roller 48 to detect the recording paper 33 .

The thermal transfer section 36 includes the above-mentioned head 2o and platen p-
A pair with 2-24 is provided. In addition, the recording paper 33
and a pressure contact row 2- for clamping the ink film 41.
48 are arranged. Note that arrow B in the drawings indicates that a pressure contact drive mechanism is provided.

What should be noted about such a thermal recording device 39 is that
As shown in an enlarged view in FIG. 12, a recording paper 33 and an ink film 41 are placed between the platen roller 24 and the head 20.
and are held at the position of the heat generating part 2 to perform recording (that is, the heat-melting ink 50 on the ink film 41 is selectively heated and melted to form a recording pattern 50' on the recording paper 33).
1) Based on the head configuration as described above, the heat generating section 2 can be provided on the left end side of the head in the figure, so the recording paper 33 can be taken out of the head 20 immediately after recording.

As a result, the recorded pattern 50 on the recording paper 33 can be visually observed within a short time after recording, which is extremely convenient. On the other hand, when the heat generating part is located in the middle of the head as in a conventional head, there is a distance between the heat generating part and the end of the head of approximately Therefore, it takes a corresponding amount of time for the recording paper to come out immediately after recording, which creates a problem that it is difficult for the user to handle it.

FIG. 13 shows a thermal recording device g1.59 using thermal paper. According to this, thermal paper 51 is fed out from a supply roller 52 in a case 53, and a head 20 and a platen roller 54 are connected to each other. The head 20 selectively develops color by heating the head 20. Then, this thermal paper is discharged from between transport p-2-55 and 56 with the image recorded as a color pattern.

Although the present invention has been illustrated above, the above-mentioned example can be further modified based on the technical idea of the present invention.

For example, the arrangement, shape, layer structure, material, electrical connection method, etc. of the heat generating part and the IC part may be changed.

Only one printed circuit board may be used over the entire length of the head. In addition, the above-mentioned power distribution &! 17 is tape 70
It may be provided on both the front and back surfaces.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a schematic perspective view of a part of a thermal recording head, FIG. 2 is an enlarged plan view of FIG. 1, and FIG. 3 is a main part of FIG. 2. 4 is a sectional view taken along the line X-X of FIG. 3, FIG. 5 is a sectional view taken along the Y-Y line of FIG. 3, and FIG. 6 is a sectional view taken along the z-2 line of FIG. FIG. 7 is a plan view similar to FIG. 3 of another thermal recording head, FIG. 8 is a plan view similar to FIG. 3 of another thermal recording head, and FIG. 10 is a sectional view taken along the line Y'-Y' of FIG. 8, FIG. 11 is a schematic sectional view of the entire thermal transfer recording device, and FIG. 12 is the main part of FIG. The enlarged view, FIG. 13, is a schematic sectional view of the entire thermal recording apparatus using thermal paper. In addition, in the symbols shown in the drawings, 1...Base 2...Heating part 3...Resistor plate 4・・・・・・・・・・IC chip 5・・・・・・・・Printed circuit board 7・・・・・・・・・・Film carrier tape 8・・・・
...Heating element layer 9 ...... Ground electrode 10 ...... Signal electrode (wiring) 12.16
．． 1B・・・・・・・・・Wiring 13・・・・・・・・・
...Wire 15...Lead 17...Power supply wiring 20...Thermal recording head 24.54.
・・・・・・・・・Platen 33・・・・・・・・・・
Recording paper 50'... Recording pattern 51...
...It's thermal paper. Agent Patent Attorney Hiroshi Aisaka (1 other person) 31st month -

Claims (1)

[Claims] 1. A heat generating section and an integrated circuit section that operates the heat generating section are provided on a common support, and the signal electrode wiring to the heat generating section and the integrated circuit section are electrically connected to each other via a film carrier tape. 1. A thermal recording head, characterized in that the common electrode wiring of the integrated circuit section is provided on the back side and/or the front side of the film carrier tape.